\begin{tabular}{l*{7}{c}}
\toprule
                    &\multicolumn{1}{c}{1963-1987}&\multicolumn{1}{c}{1963-2016}&\multicolumn{1}{c}{1963-1987}&\multicolumn{4}{c}{1963-2016}                      \\\cmidrule(lr){2-2}\cmidrule(lr){3-3}\cmidrule(lr){4-4}\cmidrule(lr){5-8}
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}&\multicolumn{1}{c}{(5)}&\multicolumn{1}{c}{(6)}&\multicolumn{1}{c}{(7)}\\
\midrule
Relative supply of college workers&      -0.781&      -0.411&      -0.687&      -0.632&      -0.703&      -0.608&      -0.541\\
                    &     (0.186)&     (0.064)&     (0.137)&     (0.069)&     (0.077)&     (0.104)&     (0.067)\\
\addlinespace
Real minimum wage   &            &            &      -0.311&      -0.220&      -0.199&      -0.133&            \\
                    &            &            &     (0.064)&     (0.048)&     (0.059)&     (0.052)&            \\
\addlinespace
Real federal minimum wage&            &            &            &            &            &            &      -0.161\\
                    &            &            &            &            &            &            &     (0.044)\\
\addlinespace
Time                &       0.027&       0.016&       0.021&       0.021&            &            &       0.019\\
                    &     (0.006)&     (0.001)&     (0.005)&     (0.002)&            &            &     (0.002)\\
\addlinespace
Constant            &      -0.004&       0.007&       0.017&       0.009&      -0.000&       0.033&       0.010\\
                    &     (0.021)&     (0.008)&     (0.018)&     (0.007)&     (0.014)&     (0.027)&     (0.007)\\
\midrule
Time Polynomial     &           1&           1&           1&           1&           2&           3&           1\\
Observations        &          25&          54&          25&          54&          54&          54&          54\\
\textit{R}-squared  &       0.271&       0.936&       0.636&       0.957&       0.957&       0.966&       0.951\\
\bottomrule
\end{tabular}
